The present invention relates generally to an elongated length of a single or double-sided stretch releasing adhesive tape that can be cut to a selected length with integral pull tabs for stretch removing the tape from a substrate.
Stretch releasing adhesive tapes represent an emerging class of high performance pressure-sensitive adhesives combining strong holding power with clean removal and no surface damage. Such stretch releasing adhesive tapes are useful in a wide variety of assembling, joining, attaching, and mounting applications.
Adhesive tape strips that can be cleanly removed from a surface by stretching the tape strip are known in the patented prior art. The Korpman U.S. Pat. No. 4,024,312, for example, discloses a highly conformable adhesive tape including a highly extensible and elastic backing film laminated with an adhesive layer. The backing film possesses a lengthwise elongation at break of at least about 200%. The tape is easily stretchable and may be removed from a surface by stretching the tape lengthwise in a direction substantially parallel to the surface. German Patent No. 33 31 016 discloses a high elasticity, low plasticity adhesive film based on a thermoplastic rubber and tackifying resins, wherein the adhesive bond can be broken by stretching the adhesive film in the direction of the plane of the adhesive bond.
The Kreckel et al. U.S. Pat. No. 5,516,581, assigned to the same assignee as the present invention, discloses a removable adhesive tape having a highly extensible and substantially inelastic backing coated with a layer of pressure sensitive adhesive. The adhesive tape can be removed from a substrate without damaging the substrate by stretching the tape in a direction substantially parallel to the surface of the substrate. The tape backing has a lengthwise elongation at break of from about 150% to about 1200%, a Young""s modulus of at least about 2,500 psi to about 72,500 psi, and an elastic recovery of less than about 50% after being stretched and removed. PCT International Publication No. WO 95/06691 discloses a removable foam adhesive tape comprising a backing including a layer of polymeric foam, and a layer of pressure-sensitive adhesive coated on at least one surface of the backing. The foam-layer of the backing has a thickness of about 30 to about 1000 mils, and the backing has a lengthwise elongation at break of from about 50% to about 1200%, and a Young""s modulus of less than about 2,400 psi.
Commercial stretch releasing adhesive tapes include the product sold under the trade designation COMMAND by Minnesota Mining and Manufacturing Company, St. Paul, Minn., and the product sold under the trade designation POWER-STRIPS by Beiersdorf AG, Hamburg, Germany. These products are currently manufactured as discrete strips with one end of the strip including a non-adhesive pull tab to facilitate stretching of the strip during removal. The adhesive surfaces of the strip are additionally protected with a release liner.
Desirable for certain applications is an elongated stretch releasing adhesive tape strip of indefinite length which can be formed into a roll or stack from which segments of selected length can be cut depending on the end use application. The difficulty with providing a long length of stretch releasing tape which can be cut to a selected length is the ability to provide a non-adhesive pull tab at a specific location on the cut strip to serve as a grasping area for stretching the strip from a surface at the time of removal.
PCT International Publication No. WO 98/06652 discloses a length cutting fixture which can be used to form a non-adhesive pull tab or xe2x80x9cgripperxe2x80x9d at the end of a long length of a conventional single-sided adhesive tape. The length cutting fixture also serves to cut the long length of tape, now including the gripper, to any selected length. The gripper is formed by folding the end of the tape back onto itself Such a length cutting fixture, however, cannot be used to form a non-adhesive pull tab on a double-sided adhesive tape.
It is therefore desirable to provide a single or double sided-stretch releasing adhesive tape article in a long length which can be cut into discrete strips having any selected length, wherein each strip can be provided with a non-adhesive pull tab or stretch removal tab that can be grasped and pulled by a user to remove the adhesive tape from a substrate.
The present invention relates generally to an elongated strip of a single or double-sided stretch releasing adhesive tape of indefinite length having one or more integral non-adhesive pull tabs arranged along its length, whereby tape segments each having at least one non-adhesive pull tab for stretch removing the tape segment from a substrate can be cut from the elongated strip. The present stretch releasing adhesive tape invention can be provided as long strips, in roll form, or in a stack. Additionally, the present invention can be used with any known stretch releasing adhesive tape, including a pressure sensitive adhesive tape with an elastic backing, a pressure sensitive adhesive tape with a highly extensible and substantially inelastic backing, or a solid, elastic pressure sensitive adhesive.
The elongated stretch releasing adhesive tape article generally includes an elongate length of stretch releasing adhesive tape defining a longitudinal axis and including first and second surfaces. The first surface comprises one or more adhesive regions and one or more non-adhesive regions arranged along the longitudinal axis. To form a single-sided tape, the second surface can be non-adhesive or can be provided with a coating to render the second surface non-adhesive. To form a double-sided tape, the second surface can include adhesive and non-adhesive regions that generally correspond to those on the first surface. At least a portion of the first surface non-adhesive regions comprise a series of pull tabs arranged along the longitudinal axis that can be grasped in combination with a second surface non-adhesive region and stretched in the longitudinal direction by a user during stretch removal of the tape from an associated substrate.
In one embodiment, the first surface is releasably adhered to the second surface which includes a low adhesion backsize to form a roll or stack of stretch releasing adhesive tape. Alternatively, elongated strips of the stretch releasing adhesive tape can be formed by releasably adhering a liner to the first surface to protect the adhesive thereon. The liner can optionally be stretchable or extensible.
In another embodiment, the one or more non-adhesive regions comprise a plurality of discrete non-adhesive regions arranged along the longitudinal axis. The discrete non-adhesive regions can extend generally perpendicular from the longitudinal axis. In another embodiment, the one or more non-adhesive regions comprise an elongated non-adhesive region arranged generally parallel to the longitudinal axis. In one embodiment, the elongated non-adhesive regions comprise a continuous region. In yet another embodiment, the one or more non-adhesive regions comprise an elongated non-adhesive region generally parallel to a first side edge of the stretch releasing adhesive tape and the one or more adhesive regions comprise an elongated adhesive region generally parallel to a second side edge of the stretch releasing adhesive tape.
In yet another embodiment, the one or more non-adhesive regions comprise an elongated non-adhesive region parallel to the longitudinal axis and interposed between a pair of elongated adhesive regions arranged generally parallel to first and second side edges, respectively, of the stretch releasing adhesive tape. Conversely, the one or more adhesive regions can comprise an elongated adhesive region parallel to the longitudinal axis and interposed between a pair of elongated non-adhesive regions arranged generally parallel to first and second side edges, respectively, of the stretch releasing adhesive tape.
The one or more non-adhesive regions can be one or more gaps in an adhesive defining the adhesive region. Alternatively, the one or more non-adhesive regions can comprise one or more appliques. In one embodiment, the appliques can be arranged intermittently along a continuous adhesive region. In another embodiment, the appliques comprise elongated appliques arranged generally parallel to the longitudinal axis. The appliques can be conventionally known materials or coatings, such as film, paper, powder, foam, ink or a release liner, applied to the tape to render a region non-adhesive. Frangible connections, which serve to define the length of the tape segments and the shape of the pull tabs, can optionally be formed intermittently along the stretch releasing adhesive tape and liner.
In another embodiment, the elongated stretch releasing adhesive tape article includes an elongate length of stretch releasing adhesive tape defining a longitudinal axis. The stretch releasing adhesive tape has first and second opposing surfaces. The first and second surfaces comprise one or more adhesive regions and one or more non-adhesive regions arranged along the longitudinal axis. At least a portion of the non-adhesive regions comprise a series of pull tabs arranged along the longitudinal axis that can be grasped by a user during stretch removal of the tape from an associated substrate. A liner having a first low adhesion surface is releasably bonded to the second adhesive surface.
In one embodiment, the first surface is releasably adhered to a second surface of the liner comprising a roll of stretch releasing adhesive tape. In another embodiment, a liner is releasably adhered to the first surface.